Method and apparatus for making netlike structures from preformed strands

ABSTRACT

Method and apparatus for making netlike structures from preformed strands by repeatedly revolving strands of each pair of a plurality of pairs of preformed strands alternately with relatively moving the strands of such pairs of strands into positions as to arrange the strands into different pairs.

United States Patent Inventor Warren H. Guy

Glen Mills, Pa.

Appl. No. 825,211

Filed May 16, 1969 Patented Dec. 28, 1971 Assignee FMC Corporation Philadelphia, Pa.

METHOD AND APPARATUS FOR MAKING NETLIKE STRUCTURES FROM PREFORMED STRANDS 10 Claims, 4 Drawing Figs.

US. Cl 87/12, 87/53, 264/103 Int. Cl D04g 1/00 Field of Search 87/12, 53; 264/ 103 [56] References Cited UNITED STATES PATENTS 1,110,718 9/1914 Saunders.. 87/53 2,760,402 8/1956 Ederer 87/12 X 3,331,903 7/1967 Mine 264/103 3,518,720 7/1970 Fairbanks 87/12 X Primary Examiner-John Petrakes Att0rneys-Thomas R. OMalley, George F. Mueller and Eugene G. Horsky ABSTRACT: Method and apparatus for making netlike structures from preformed strands by repeatedly revolving strands of each pair of a plurality of pairs of preformed strands alternately with relatively moving the strands of such pairs of strands into positions as to arrange the strands into different pairs.

PATENTEB naczs :an

METHOD AND APPARATUS FOR MAKING NETLIKE STRUCTURES FROM PREFORMED STRANDS The present invention is directed to an improved method and apparatus for making netlike structures by interlacing and/or twisting preformed strands with each other.

In U. S. Pat. No. 3,331,903, there is disclosed a method and apparatus for making a net from plastic material by extruding a plurality of pairs of filaments of plastic material in such a manner that the filaments in each pair are spaced from each other in a first direction and the pairs of filaments are spaced from each other a given distance in a second direction. The filaments of each pair of filaments are revolved at the moment of their extrusion and before being solidified about an axis extending between the filaments of each pair of filaments so as to twist the filaments of each pair together and to thus integrally connect the filaments.- One of the filaments of each pair of filaments is then moved in a second direction a distance equal to the spacing between pairs of filaments while continuing the extrusion of the filaments, after which pairs of filaments are again revolvedas heretofore described. By continuously repeating the above steps and setting of the extruded filaments of plastic material, a netlike structure is provided.

The method and apparatus disclosed in the above-noted patent are useful only in making netlike structures having integral junctions by twisting together freshly extruded monofilaments while they are still in a plastic condition.

A primary object of the present invention is the provision of an improved and more satisfactory method and apparatus for making netlike structures from preformed strands.

Another object is to provide an improved method and apparatus for making continuous netlike structures of woven or braided construction by interlacing preformed strands with each other.

Still another object is to provide an improved method and apparatus for making continuous netlike structures of flat or tubular construction by twisting preformed strands with each other.

A further object is the provision of an improved method and apparatus in which preformed strands may be coated concomitantly with interlacing and/or twisting of the same into netlike structures.

These and other objects are accomplished in accordance with the present invention by a method and apparatus in which preformed strands are continuously drawn from individual supply sources and arranged as a plurality of pairs, with the strands in each pair being spaced from each other in a first direction and the pairs of strands themselves being spaced a given distance from each other in a second direction. The strands of each pair are engaged at substantially like locations along their lengths and each individual pair is revolved about an axis between the strands thereof so that the strands of each pair of strands at least exchange positions with each other. Again at the locations at which the strands are engaged, relative movement is imparted to the strands of each pair of strands in the second direction so as to arrange at least certain of the strands of each pair of strands into different pairs. The individual strand supply sources are moved concomitantly with and in the same directions as the respective strands which are withdrawn therefrom. By continuously repeating the above sequence of movements of strands and strand supply sources. a netlike structure is provided.

More particularly, the strands of each pair of strands are moved through an angle of 180 or a further multiple thereof during each revolution of such pairs of strands. The strands of each pair of strands may be moved through an angle of only 180, providing that the direction of relative movement of the strands in the second direction and the direction of revolution of such pairs of strands be reversed after the respective alternate movement has been completed. That is, the relative movement of the strands in each pair of strands in a second direction is effected alternately with revolving of the strands in each pair of strands. Thus, if the direction of relative movement of the strands is reversed after each revolution of the strands in each pair of strands, and the direction of revolution of the strands of each pair of strands is reversed after each relative movement of the strands, then each revolution of the strands may be limited to only l and will result in the production of a netlike structure which is of woven or braided construction.

On the other hand, revolving the pairs of strands through an angle of 360 or further multiple of 180 will cause the strands of each pair of strands to be twisted together and will result in a netlike structure having good strength, yet is flexible. Arranging the pairs of strands in a circular array and revolving each such pair of strands through an angle of only 360 or further multiple of 360 will also cause the strands of each such pair to be twisted together and will result in a netlike structure which is of tubular construction.

The preformed strands may be coated or impregnated with any desired finished concomitantly with their withdrawal from the individual supply sources. Such coating material may perhaps consist of an adhesive which will effect bonding of the strands as they are interlaced and/or twisted together.

The apparatus of the present invention includes separate means for supporting each of a plurality of strand packages and a plurality of strand guides, each having an opening through which are laced individual strands drawn from the separate strand packages. The strand guides are arranged in pairs with the openings in each pair of guides being spaced from each other a given distance in a first direction and with the pairs of guides being spaced from each other a given distance in a second direction. Means are provided for periodically revolving each pair of strand guides through an angle equal to a multiple of 180 about an axis located between the respective guides of each pair of guides. Operative alternately with the revolving means are means for relatively shifting the guides of each pair of guides in a second direction to arrange at least certain of the guides into different pairs. Means also are provided for moving the supporting means for the strand packages concomitantly with and in the same direction as the strand guides containing the strands drawn from the respective strand packages.

The pairs of strand guides may be arranged in a circular array and in this instance the revolving means is such as to move the strand guides of each pair of strand guides through an angle of 360 or further multiple of 360.

The means for relatively shifting the strand guides includes a pair of plates which are disposed in a common plane and have edges thereof disposed in abutting relationship. Like semicircular recesses are formed at spaced intervals along the abutting edges of such plates. The strand guides are of semiciruclar configuration and are received within the recesses of the plates.

The supporting means for the strand packages includes a pair of platforms which are disposed in a common plane with edges thereof in abutting relationship. Like semicircular recesses are formed at spaced intervals along the abutting edges of such platforms and a semicircular table, on which a strand package may be supported, is disposed in each of such recesses. Means are provided for relatively shifting the platforms and for revolving the package support tables.

As in conventional apparatus for making netlike structures, suitable means are provided for drawing the finished netlike structure away from the means which forms the netlike structure itself.

The term strand as used throughout the description and claims is intended to include monofilaments as well as yarns formed from continuous filaments or from stable fibers. The strands which are to be incorporated into netlike structures need not be formed of like material and may vary in characteristics such as size, strength, color, finish, etc. Strands which are formed of synthetic molecularly orientable materials may be stretched during their manufacture to provide resulting netlike structures having excellent strength characteristics.

The teachings of the present invention are applicable for use with a variety of strand materials, including materials which are thermoplastic, such as polyamides or superpolyamides, polyesters, polyvinyl chloride, copolymers thereof, polyolefins, cellulose acetates, etc., natural or synthetic rubbers, thermosetting materials or wet-spinnable materials, such as viscose, cuproammonium cellulose, or carboxymethyl cellulose. Such materials may include various additives such as stabilizers, dyes, foaming agents, etc., if so desired.

For a greater understanding of this invention, reference is made to the following detailed description and drawing in which FIG. 1 is a vertical section taken transversely of the apparatus of the present invention;

FIG. 2 is a top view of a portion of the apparatus shown in FIG. 1;

FIG. 3 is a top view of a portion of the apparatus shown in FIG. 1 as viewed along the line IlI-lll; and

FIG. 4 is a perspective view of elements of the apparatus removed from the remainder thereof.

The apparatus shown in the drawing includes a troughlike member having sidewalls 17 and 19, end walls 21 and 23 and a bottom wall 25. Walls 27 and 29 extend along the entire length of the member 15 and define a slot 31 in its bottom wall 25. The walls 27 and 29 are both rabbeted at 33 for slidablyv supporting a pair of elongated plates 35 and 37 which extend along the entire length of the slot 31 and project beyond the opposite end walls 21 and 23 of the member 15. The slotted member 15, together with the plates 35 and 37, define a chamber 39 for containing a liquid 41, as hereafter described. Suitable gaskets may be provided along the areas of the end walls 21 and 23 which are adjacent to the plates 35 and 37 to prevent leakage of liquid from the chamber 39.

Contacting parallel edges 43 and 45 of the plates 35 and 37 together define a common plane and are each formed with a series of like, equally spaced, semicircular recesses 47. A stand guide 49 is received within each of the plate recesses 47 and, as best shown in FIG. 4, includes a flat wall 51, an arcuate wall 53 which conforms with the contour of the plate recesses 47, and a flange 55 at its uppermost end which is adapted to rest upon the top surfaces of the plates 35 and 37. Each of the strand guides 49 has an opening 57 which extends therethrough and a series of gear teeth 59 along its arcuate wall 53, at a location as to be exposed below the bottom surfaces of the plates 35 and 37.

With the flat sides 51 of the opposing strand guides 49 aligned with each other and with the opposing edges 43 and 45 of the plates 35 and 37, at least one and preferable both of such plates, and the guides 49 positioned therein, are moved or shifted longitudinally relative to each other. This relative longitudinal movement of the plates 35 and 37 is effected by pins 61 and 63 which project from the respective plates 35 and 37 and ride along grooves 65 and 67 formed in opposing faces of cams 69 and 71. The cams 69 and 71 are of like construction and are fixed, in 180 out-of-phase relationship, to a shaft 73 which is supported by bearings and intermittently driven by suitable means, not shown. As more fully described hereafter, the plates 35 and 37 are moved a distance substantially equal to one-half of the center-to-center spacing of the recesses 47 therein, or multiple of such spacing, so as to move the guides 49 which are carried by such plates into different positions of alignment with each other.

Alternately with the longitudinal sliding movement of the plates 35 and 37, aligned guides 49 carried by such plates are together revolved as a unit through an angle of 180 or further multiple thereof so as to at least exchange the positions of such pair of aligned guides. If in the practice of the method of the present invention the guides are revolved through an angle of only 180 each such revolving movement is in a direction opposite to the previous revolving movement thereof so as to provide for interlacing of strands, as more fully described hereafter.

Revolving of aligned pairs of guides 49 is effected by racks 75 and 77 which mesh with the gear teeth 59 projecting from the arcuate walls 53 of the guides 49. Preferably, the walls 27 and 29 are rabbeted at 79 to provide channels along which the racks 75 and 77 may be reciprocated. The racks 75 and 77 are themselves intermittently driven by gears 81 and 83, respectively, which are fixed to shafts and 87.

In the arrangement illustrated in the drawing, the racks 75 and 77 are designed to revolve aligned guides 49 through an angle of only 180 alternately with the shifting of the plates 35 and 37, and thus gear teeth are present only along selected lengths of the racks 75 and 77 and are omitted from portions indicated at 89 and 91. To provide for movement of the racks 75 and 77 a distance necessary for revolving aligned guides 49 through an angle of only 180 the gears 81 and 83 may be in the form of segment gears which are intermittently driven by oscillating the shafts 85 and 87 in opposite directions.

I Preformed strands 93 are drawn from separate strand packages 95 and are laced through the openings 57 in the strand guides 49. The strand packages 95 are positioned on semicircular tables 97 which are themselves received within semicircular recesses 99 formed at spaced intervals along the abutting edges 101 and 103 of the platforms 105 and 107. Each table 97 inches a flange 109 which rests on the platforms 105 and 107 and an opening 111. A fixed framework, shown in part at 113 is rabbeted at 115 and supports the platforms 105 and 107 for longitudinal shifting movement.

It is intended that the tables 97 and the platforms 105 and 107 be moved concomitantly with and in the same directions as the strand guides 49 and the plates 35 and 37, respectively. Thus, the tables 97 are each formed with gear teeth 117 which mesh with racks I19 and 121. The racks 119 and 121 themselves are moved, as by segment gears not shown, simultaneously with and in the same directions as the racks 75 and 77 heretofore described, to revolve the pairs of aligned tables 97. Alternately with the movement of such tables, the platforms 105 and 107 are shifted simultaneously with and in the same directions as the plates 35 and 37, as by means of cams similar to cams 69 and 71 heretofore described.

In the practice of the method of the present invention with the specific apparatus described above, individual preformed strands 93 are drawn from separate supply packages 95, passed through the table openings 111, and laced through openings 57 in the strand guides 49. With the elements of the apparatus in positions as shown in FIG. 3, the racks 75 and 77 and also the racks 119 and 121 are driven to simultaneously revolve aligned pairs of strand guides 49 and aligned pairs of tables 97 in the same direction and through an angle of By this movement, the strand guides 49 of each pair of aligned pair of strand guides and the strands 93 therethrough reverse positions. Also, the strand packages 95, from which such strands 93 are drawn, also reverse positions.

With the strand guides 49 and tables 97 now held stationary, the plates 35 and 37 are shifted longitudinally in opposite directions relative to each other by the cams 69 and 71 to align different of the strand guides 49 carried by such plates. Concomitantly with the shifting of the plates 35 and 37. the platforms 105 and 107 are moved in the same directions and to the same extent as the plates 35 and 37.

Again with the plates 35 and 37 and the platforms 105 and 107 held fixed, the racks 75 and 77 are driven to revolve the now aligned strand guides 49 through an angle of only 180. The direction of revolution of such aligned strand guides, however, is in a direction opposite to that in which aligned strand guides were previously revolved. The racks 119 and 121 are driven simultaneously with the racks 75 and 77 to revolve the tables 97 in the same directions and to the same extent as the strand guides. By continuously repeating the above-described steps, a netlike structure results in which the strands are interlaced with each other.

If desired a coating liquid such as a strand finish or adhesive may be contained with the chamber 39 to coat the strands as they are drawn from the strand packages and passed to the strand guides.

As heretofore mentioned, in lieu of revolving the aligned strand guides 49 and tables 97 through an angle of only 180, the guides and tables may be turned through 360 or further multiple of 180 to provide a netlike structure in which the individual strands are twisted with each other at their crossing points. Moreover, if the movement of the guides 49 and tables 97 is limited to complete 360 turns or further multiples thereof, the various elements of the apparatus may be arranged in a circular array to thereby produce tubular netlike structures in which the strands are twisted with each other at their points of crossing.

lclaim:

1. A method of making netlike structures from preformed strands including the steps of continuously drawing preformed strands from individual supply sources and arranging the same as a plurality of pairs with strands in each pair being spaced from each other in a first direction and the pairs of strands being spaced a given distance in a second direction, at locations spaced from the individual supply sources engaging the strands of each pair of strands while maintaining their spaced relationship and at such locations revolving each individual pair about an axis extending between the strands thereof so that the strands of each such pair of strands at least exchange positions relative to each other, at the locations at which the strands are engaged relatively moving the strands of each pair of strands in the second direction to arrange at least certain of the strands of each pair of strands into different pairs of strands, moving the individual strand supply sources concomitantly with and in the same directions as the respective strands which are withdrawn therefrom, and continuously repeating the above sequence of movements of strands and strand supply sources.

2. A method as defined in claim 1 wherein the strands of each pair of strands and the supply sources of such respective strands are moved through an angle equal to a multiple of 180 during each revolution thereof.

3. A method as defined in claim 1 wherein relative movement of the strands of each pair of strands is effected by moving such strands oppositely of each other in the second direction and the strands of each pair of strands are moved through an angle equal to only 180 during each revolution thereof, with the movement of the strands in the second direction and the revolving movement of the pairs of strands occurring in alternate relationship and with each such movement being reversed after the respective alternate movement is completed.

4. A method as defined in claim I wherein the strands of each pair of strands are revolved through an angle equal to a multiple of 360 and wherein the pairs of strands are arranged in a circular array whereby the resulting netlike structure is of tubular construction.

5. A method as defined in claim 1 further including the step of passing the strands through a bath of coating material as they are continuously drawn from the individual strand supply sources and arranged in pairs.

6. Apparatus for making netlike structures from preformed strands including separate means for supporting each of a plurality of strand packages, a plurality of strand guides each having an opening through which are laced individual strands drawn from the separate strand packages, said strand guides being arranged in pairs with the openings in each pair of guides being spaced from each other a given distance in a first direction and the pairs of guides being spaced from each other a given distance in a second direction, means for periodically revolving each pair of strand guides through an angle equal to a multiple of about an axis located between the respective guides of each pair of guides, means operative alternately with the revolving means for relatively shifting the guides of each pair of guides in the second direction to arrange at least certain of the guides into different pairs, and means for moving the supporting means for the strand packages concomitantly with and in the same directions as the strand guides containing the strands drawn from the respective of such packages.

7. Apparatus as defined in claim 6 wherein the pairs of strand guides are arranged in a circular array and wherein the revolving means rs adapted to move the strand guides through an angle of a multiple of 360.

8. Apparatus as defined in claim 6 wherein the shifting means includes a pair of plates disposed in a common plane and having edges thereof disposed in abutting relationship and like semicircular recesses formed at spaced intervals along the abutting edges of such plates, and wherein the strand guides are of semicylindrical configuration and are received within the recesses of said plates.

9. Apparatus as defined in claim 8 wherein said supporting means for the strand packages includes a pair of platforms disposed in a common plane with edges thereof in abutting relationship, like semicircular recesses formed at spaced intervals along the abutting edges of said platforms, and a semicircular table disposed in each of the recesses in said platforms and on which a strand package may be supported, and wherein the said supporting means includes means for relatively shifting said platforms and means for revolving said tables.

10. Apparatus as defined in claim 8 further including means cooperating with said plates to provide a chamber for containing a coating bath. 

2. A method as defined in claim 1 wherein the strands of each pair of strands and the supply sources of such respective strands are moved through an angle equal to a multiple of 180* during each revolution thereof.
 3. A method as defined in claim 1 wherein relative movement of the strands of each pair of strands is effected by moving such strands oppositely oF each other in the second direction and the strands of each pair of strands are moved through an angle equal to only 180* during each revolution thereof, with the movement of the strands in the second direction and the revolving movement of the pairs of strands occurring in alternate relationship and with each such movement being reversed after the respective alternate movement is completed.
 4. A method as defined in claim 1 wherein the strands of each pair of strands are revolved through an angle equal to a multiple of 360* and wherein the pairs of strands are arranged in a circular array whereby the resulting netlike structure is of tubular construction.
 5. A method as defined in claim 1 further including the step of passing the strands through a bath of coating material as they are continuously drawn from the individual strand supply sources and arranged in pairs.
 6. Apparatus for making netlike structures from preformed strands including separate means for supporting each of a plurality of strand packages, a plurality of strand guides each having an opening through which are laced individual strands drawn from the separate strand packages, said strand guides being arranged in pairs with the openings in each pair of guides being spaced from each other a given distance in a first direction and the pairs of guides being spaced from each other a given distance in a second direction, means for periodically revolving each pair of strand guides through an angle equal to a multiple of 180* about an axis located between the respective guides of each pair of guides, means operative alternately with the revolving means for relatively shifting the guides of each pair of guides in the second direction to arrange at least certain of the guides into different pairs, and means for moving the supporting means for the strand packages concomitantly with and in the same directions as the strand guides containing the strands drawn from the respective of such packages.
 7. Apparatus as defined in claim 6 wherein the pairs of strand guides are arranged in a circular array and wherein the revolving means is adapted to move the strand guides through an angle of a multiple of 360* .
 8. Apparatus as defined in claim 6 wherein the shifting means includes a pair of plates disposed in a common plane and having edges thereof disposed in abutting relationship and like semicircular recesses formed at spaced intervals along the abutting edges of such plates, and wherein the strand guides are of semicylindrical configuration and are received within the recesses of said plates.
 9. Apparatus as defined in claim 8 wherein said supporting means for the strand packages includes a pair of platforms disposed in a common plane with edges thereof in abutting relationship, like semicircular recesses formed at spaced intervals along the abutting edges of said platforms, and a semicircular table disposed in each of the recesses in said platforms and on which a strand package may be supported, and wherein the said supporting means includes means for relatively shifting said platforms and means for revolving said tables.
 10. Apparatus as defined in claim 8 further including means cooperating with said plates to provide a chamber for containing a coating bath. 